org.eclipse.linuxtools.lttng.ui/src/org/eclipse/linuxtools/lttng/ui/views/histogram/HistogramRequest.java

   1 /*******************************************************************************
   2  * Copyright (c) 2009 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   William Bourque - Initial API and implementation
  11  *******************************************************************************/
  12 package org.eclipse.linuxtools.lttng.ui.views.histogram;
  13
  14 import org.eclipse.linuxtools.lttng.event.LttngEvent;
  15 import org.eclipse.linuxtools.tmf.event.TmfTimeRange;
  16 import org.eclipse.linuxtools.tmf.request.ITmfDataRequest;
  17 import org.eclipse.linuxtools.tmf.request.TmfEventRequest;
  18
  19 /**
  20  * <b><u>HistogramRequest</u></b>
  21  * <p>
  22  * Request class, to perform a request to TMF for the histograms.
  23  * <p>
  24  */
  25 public class HistogramRequest extends TmfEventRequest<LttngEvent> {
  26         protected HistogramContent histogramContent = null;
  27
  28         protected int   lastInterval = 0;
  29         protected long          lastRangeTime = 0L;
  30         protected long          nbEventsInInterval = 0L;
  31
  32         protected int   nbIntervalNotEmpty = 1;
  33         protected int   nbEventRead = 0;
  34
  35         protected int   lastDrawPosition = 0;
  36
  37         protected HistogramCanvas parentCanvas = null;
  38
  39         /**
  40          * Constructor for HistogramRequest.<p>
  41          * Prepare the request in TMF and reset the histogram content.
  42          *
  43          * @param range                         Range of the request.
  44          * @param nbRequested           Nb events requested. Can be "Infinity" for all.
  45          * @param newParentCanvas       HistogramCanvas related to the request.
  46          * @param timeInterval          Time interval to consider (i.e. : 1 interval is 1 bar in the histogram)
  47          *
  48          * @see org.eclipse.linuxtools.tmf.request.TmfEventRequest
  49          */
  50         public HistogramRequest(TmfTimeRange range, int nbRequested, HistogramCanvas newParentCanvas, long timeInterval, ITmfDataRequest.ExecutionType execType) {
  51         super((Class<LttngEvent>)LttngEvent.class, range, nbRequested, HistogramConstant.MAX_EVENTS_PER_READ, execType);
  52
  53         // *** FIXME ***
  54         // This does not work! The request won't be processed or the number of events returned is wrong!
  55         // We cannot use this !
  56                 //super((Class<LttngEvent>)dataType, range);
  57
  58         parentCanvas = newParentCanvas;
  59         histogramContent = parentCanvas.getHistogramContent();
  60
  61         // Reset the content of the HistogramContent... the given data better be valid or this will fail.
  62         histogramContent.clearContentData();
  63         histogramContent.resetTable(range.getStartTime().getValue(), range.getEndTime().getValue(), timeInterval);
  64
  65         lastRangeTime = range.getStartTime().getValue();
  66
  67         // Notify the UI even before the request started, so we set the timestamp already.
  68         parentCanvas.notifyParentUpdatedInformationAsynchronously();
  69     }
  70
  71         /**
  72          * HandleData function : will be called by TMF each time a new event is receive for the request.<p>
  73          * Calculation for the content is done here.
  74          */
  75         @Override
  76     public void handleData() {
  77         LttngEvent[] result = getData();
  78         LttngEvent event = (result.length > 0) ? result[0] : null;
  79
  80         // *** FIXME ***
  81         // *** EVIL BUG ***
  82         // The request by timerange only does not work! (see constructor above)
  83         //      However, the request with number of events will loop until it reach its number or EOF
  84         //  We have to filter out ourself the extra useless events!
  85         //
  86         if (event != null) {
  87
  88                 LttngEvent tmpEvent = (LttngEvent) event;
  89
  90                 // This check is linked to the evil fix mentionned above
  91                 if ( ( tmpEvent.getTimestamp().getValue() >= histogramContent.getStartTime() ) &&
  92                          ( tmpEvent.getTimestamp().getValue() <= histogramContent.getEndTime() ) )
  93                 {
  94
  95                         // Distance (in time) between this event and the last one we read
  96                         long distance = ( tmpEvent.getTimestamp().getValue() - lastRangeTime );
  97
  98                         // Check if we changed of interval (the distance is higher than the interval time)
  99                                 if  ( distance > histogramContent.getElementsTimeInterval() ) {
 100
 101                                         histogramContent.getElementByIndex(lastInterval).intervalNbEvents = nbEventsInInterval;
 102                                         lastRangeTime = tmpEvent.getTimestamp().getValue();
 103
 104                                         // * NOTE *
 105                                         // We can skip several interval at once, so we need to find what was our interval now
 106                                         lastInterval = (int)((lastRangeTime - histogramContent.getStartTime()) / histogramContent.getElementsTimeInterval() );
 107
 108                                         // *** HACK ***
 109                                         // Because of the threads, weird phenomenons seem to happen here, like a position after the
 110                                         //       element range because another request was issued.
 111                                         // This enforce the position but may result in slightly inconsistent result (i.e. a weird misplaced bar sometime).
 112                                         if ( lastInterval < 0 ) {
 113                                                 lastInterval = 0;
 114                                         }
 115                                         else if ( lastInterval >= histogramContent.getNbElement() ) {
 116                                                 lastInterval = (histogramContent.getNbElement()-1);
 117                                         }
 118
 119                                         // * NOTE *
 120                                         // We save the time we have here. This mean only the FIRST time read in an interval will be saved.
 121                                         histogramContent.getElementByIndex(lastInterval).firstIntervalTimestamp = lastRangeTime;
 122                                         histogramContent.setReadyUpToPosition(lastInterval);
 123
 124                                         nbIntervalNotEmpty++;
 125                                         nbEventsInInterval = 1L;
 126                                 }
 127                                 // We are still in the same interval, just keep counting
 128                                 else {
 129                                         nbEventsInInterval++;
 130                                 }
 131
 132                                 if ( nbEventsInInterval > histogramContent.getHeighestEventCount() ) {
 133                                         histogramContent.setHeighestEventCount(nbEventsInInterval);
 134                                 }
 135                                 nbEventRead++;
 136
 137                                 // Call an asynchronous redraw every REDRAW_EVERY_NB_EVENTS events
 138                                 // That way we don't need to wait until to end to have something on the screen
 139                                 if ( nbEventRead % HistogramConstant.REDRAW_EVERY_NB_EVENTS == 0 ) {
 140                                         redrawAsyncronously();
 141                                 }
 142                 }
 143                 }
 144         // We got a null event! This mean we reach the end of the request.
 145         // Save the last interval we had, so we won't miss the very last events at the end.
 146         else {
 147                 // Save the last events
 148                 histogramContent.getElementByIndex(lastInterval).intervalNbEvents = nbEventsInInterval;
 149                 // We reached the end of the request, so assume we fill up the content as well
 150                         histogramContent.setReadyUpToPosition(histogramContent.getNbElement());
 151
 152                         // If the interval wasn't null, count this as a "non empty" interval
 153                         if (nbEventsInInterval > 0) {
 154                                 nbIntervalNotEmpty++;
 155                         }
 156         }
 157     }
 158
 159         /**
 160          * Function that is called when the request completed (successful or not).<p>
 161          * Update information and redraw the screen.
 162          */
 163     @Override
 164     public void handleCompleted() {
 165         parentCanvas.notifyParentUpdatedInformationAsynchronously();
 166                 redrawAsyncronously();
 167     }
 168
 169     /**
 170          * Function that is called when the request completed successfully.<p>
 171          */
 172     @Override
 173     public void handleSuccess() {
 174         // Nothing different from completed.
 175     }
 176
 177     /**
 178          * Function that is called when the request completed in failure.<p>
 179          */
 180     @Override
 181     public void handleFailure() {
 182         // Nothing different from cancel.
 183     }
 184
 185     /**
 186          * Function that is called when the request was cancelled.<p>
 187          * Redraw and set the requestCompleted flag to true;
 188          */
 189     @Override
 190     public void handleCancel() {
 191         redrawAsyncronously();
 192     }
 193
 194     /**
 195          * Update the HistogramContent with the latest information.<p>
 196          * This will perform some calculation that might be a bit harsh so it should'nt be called too often.
 197          */
 198     public void updateEventsInfo() {
 199         // *** Note ***
 200         // The average number of event is calculated while skipping empty interval if asked
 201         int averageNumberOfEvents = 0;
 202         if ( HistogramConstant.SKIP_EMPTY_INTERVALS_WHEN_CALCULATING_AVERAGE ) {
 203                 averageNumberOfEvents = (int)Math.ceil((double)nbEventRead / (double)nbIntervalNotEmpty);
 204         }
 205         else {
 206                 averageNumberOfEvents = (int)Math.ceil((double)nbEventRead / (double)histogramContent.getNbElement());
 207         }
 208
 209         histogramContent.setAverageNumberOfEvents(averageNumberOfEvents);
 210
 211         // It is possible that the height factor didn't change;
 212         //              If not, we only need to redraw the updated section, no the whole content
 213         // Save the actual height, recalculate the height and check if there was any changes
 214         double previousHeightFactor = histogramContent.getHeightFactor();
 215         histogramContent.recalculateHeightFactor();
 216         if ( histogramContent.getHeightFactor() != previousHeightFactor ) {
 217                         histogramContent.recalculateEventHeight();
 218         }
 219         else {
 220                 histogramContent.recalculateEventHeightInInterval(lastDrawPosition, histogramContent.getReadyUpToPosition());
 221         }
 222
 223         lastDrawPosition = histogramContent.getReadyUpToPosition();
 224     }
 225
 226     /**
 227          * Perform an asynchonous redraw of the screen.
 228          */
 229     public void redrawAsyncronously() {
 230         updateEventsInfo();
 231         // Canvas redraw is already asynchronous
 232         parentCanvas.redrawAsynchronously();
 233     }
 234
 235 }